Power management for wireless networks

ABSTRACT

Embodiments provide techniques for device power management in wireless networks. For instance, an apparatus may include a power management module, and a transceiver module. The power management module determines a beacon interval and a wakeup interval. The transceiver module to send a transmission to one or more remote devices that includes the beacon interval and the wakeup interval. The beacon interval indicates a time interval between consecutive beacon transmissions of the apparatus, and the wakeup interval indicates a time interval between when the apparatus receives two consecutive beacons from a peer device.

BACKGROUND

Wireless communications capabilities are increasingly being integratedinto portable devices, including laptop computers, handheld devices(such as personal digital assistants (PDAs)), and mobile phones. Theintegration of such capabilities can provide users with anywhere andanytime connectivity to information resources.

Power consumption is a key feature for such devices. For instance, lowerpower consumption levels correspond to increased operational timesbetween necessary battery charging sessions. As a result of this, thedevice user's experience may be enhanced.

Wireless mesh networks operate in accordance with a decentralized andcollaborative approach. For instance, the Institute for Electrical andElectronics Engineers (IEEE) 802.11s standard provides for wirelessnetworks composed of multiple devices (called mesh points). Thesedevices form links among them. Moreover, information can be routedthrough these links in accordance with various routing protocols.

Current drafts of IEEE 802.11s (such as IEEE 802.11s Draft Standard1.08) provide power management mechanisms that aim to conserve devicepower. However, these mechanisms often result in undesirable networkoperations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numbers generally indicate identical,functionally similar, and/or structurally similar elements. The drawingin which an element first appears is indicated by the leftmost digit(s)in the reference number. The present invention will be described withreference to the accompanying drawings, wherein:

FIG. 1 is a diagram of an exemplary operational environment;

FIG. 2 is a diagram showing exemplary operational modes and states for adevice;

FIG. 3 is a flow diagram showing an exemplary device operation;

FIG. 4 is a flow diagram showing an exemplary peer link establishmentprocess;

FIG. 5 is a diagram showing exemplary device interactions;

FIG. 6 is a diagram showing a sequence of transmissions;

FIG. 7 is a diagram of an awake window information element;

FIG. 8 is a diagram of an exemplary device implementation; and

FIG. 9 is a flow diagram.

DETAILED DESCRIPTION

Embodiments provide techniques for device power management in wirelessnetworks. For instance, an apparatus may include a power managementmodule, and a transceiver module. The power management module determinesa beacon interval and a wakeup interval. The transceiver module to senda transmission to one or more remote devices that includes the beaconinterval and the wakeup interval. The beacon interval indicates a timeinterval between consecutive beacon transmissions of the apparatus, andthe wakeup interval indicates a time interval between when the apparatusreceives two consecutive beacons from a peer device. Through theemployment of such techniques efficient network operation may beadvantageously achieved.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, appearances of the phrases “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments.

FIG. 1 is a diagram of an exemplary operational environment 100 in whichthe techniques described herein may be employed. As shown in FIG. 1,this environment includes multiple devices 102 ₁-102 ₁₀. Also, FIG. 1shows peer links 104 ₁-104 ₁₇ among these devices.

A mesh network includes two or more mobile computing devices that haveset up peer links among them. Accordingly, devices 102 ₁-102 ₁₀ haveformed a mesh network 106. Therefore, devices 102 ₁-102 ₁₀ are alsoreferred to herein as mesh points (MPs) 102 ₁-102 ₁₀.

MPs 102 ₁-102 ₁₀ may each be various types of devices. Exemplary devicesinclude laptop computers, desktop computers, personal digital assistants(PDAs), Ultra-Mobile personal computers (UMPCs), and Mobile InternetDevices (MIDs). However, embodiments are not limited to these devicetypes.

Typically, mesh network operations are not determined by a centralcontroller. Instead, such decision making is usually distributed (orcollaborative) among the network's MPs. Information pertaining to suchcollaborative decision making may be exchanged among MPs throughtransmissions call beacons. During operation, the MPs independently sendout beacons at their respective target beacon transmission times(TBTTs).

Moreover, MPs, may operate in accordance with various modes and states.For example, MPs may operate in either an active mode or a power savingmode. In the active mode, an MP is continually able to exchangeinformation with other devices. However, in the power saving mode, an MPis not always available to exchange such information. Further detailsregarding active and power saving modes are described below withreference to FIG. 2.

Thus, in the context of FIG. 1, each of MPs 102 ₁-102 ₁₀ are not activeat all times. Consequently, it can be a daunting task to achievecollaboration (or distributed decision making) among MPs so that theymay operate in power saving modes.

The power management schemes proposed in the IEEE 802.11s Draft Standard1.08 are mainly based on infrastructure mode operation (in which devicescommunicate with each other through an access point). Also, this draftstandard provides an automatic power save delivery (APSD) operation(defined in section 11A. 12.6) that only works when one MP is not inpower saving mode or when there is a central control entity

Further, the IEEE 802.11s Draft Standard version 1.08 requires an MP tosynchronize with its peer MPs before entering a power saving mode. Thisdraft standard provides a peer link offset synchronization scheme toaccomplish such synchronization. The peer link offset synchronizationscheme forbids an MP from entering the power saving mode until it hasinformed all of its peer MPs through unicast messages. Unicast messagesare required in this scheme because broadcast messages are consideredunreliable and may cause ambiguity in an MP's knowledge of powermanagement states being employed by other MPs in the mesh network.

Embodiments provide advantages over existing techniques. For instance,embodiments provide completely distributed operation. In addition,embodiments facilitate flexible power management through two intervals:a beacon interval and a wakeup interval.

As described above, MPs may operate in accordance with various modes andstates. FIG. 2 is a diagram providing examples of such modes and states.In particular, FIG. 2 shows an active mode 202, and a power saving mode204.

In embodiments, an MP in power saving (PS) mode 204 may operate in oneof two states. These states are an awake state 206 and a doze state 208.In awake state 206, the MP is fully powered, and is able to transmit orreceive frames. However, in doze state 208, the MP consumes very lowpower, and is not able to transmit or receive. As indicated by arrows224 and 226, the MP may alternate between awake state 206 and doze state208 while operating in PS mode 204. This alternation may be determinedby specified time intervals, as well as by frame transmission andreception rules.

In active mode 202, the MP operates in an awake state (such as awakestate 206) all the time. As indicated by arrows 220 and 222, the MP maytransition between active mode 202 and PS mode 204. Such transitions maybe based on various factors, such as user settings.

Further details regarding MP operations in PS mode 204 are now provided.

An MP in PS mode 204 (also called a “PS MP”) transmits its own beaconsat a pre-determined beacon interval (which are indicated by targetbeacon transmission times (TBTT)). Further, the PS MIP wakes up (i.e.,enters awake state 206 from the doze state 208) to receive its peers'beacons and/or broadcast messages, and to also maintain synchronizationand peer links. A PS MP does not have to wake up to receive every beaconfrom its peers. As an example, a PS MP may instead decide to receiveevery other beacon, every delivery traffic indication message (DTIM)beacon, or every other DTIM beacon transmitted by a peer.

The time interval between when a PS MP receives two consecutive beaconsfrom a peer MP is referred to herein as the wakeup interval. The wakeupinterval is per peer link based. Thus, a PS MP may employ multiplewakeup intervals. Moreover, each wakeup interval can be negotiatedbetween the PS MP and the corresponding peer MP. Furthermore, the wakeupinterval(s) and beacon interval(s) employed by a PS MP may beimplementation dependent. For instance, wake up interval(s) and beaconinterval(s) may be based on factors, such as traffic load(s) to/frompeer MP(s), clock synchronization accuracy, user selection, and soforth.

In embodiments, an MP may define the length of its beacon interval andits wakeup interval(s) before it enters PS mode 204. Also, inembodiments, the MP may inform its peer MPs of its beacon interval andtarget beacon transmission time (TBTT). By so doing, the MP's peers canwake up at the right time to receive the MP's beacons. Optionally, anMP's wakeup interval(s) may be negotiated with its peer MP(s). Throughsuch negotiations, the peer MP(s) may schedule their broadcasttransmission(s) to the PS MP. Further, a PS MP may also request its peerMPs to send broadcast traffic as unicast frames to itself.

In embodiments, a PS MP advertises an Awake Window in its beacon. Theawake window may be indicated in an information element (IE), such asthe IE of FIG. 7. However, other forms of indication may be employed.The start of the Awake Window is measured from PS MP's TBTT. Thisadvertised awake window indicates how long the PS MP will remain awakeafter sending a beacon. In contrast, a conventional PS MP returns todoze state 208 right after sending its beacon.

FIG. 3 illustrates an embodiment of a logic flow. In particular, FIG. 3illustrates a logic flow 300, which may be representative of theoperations executed by one or more embodiments described herein.Although FIG. 3 shows a particular sequence, other sequences may beemployed. Also, the depicted operations may be performed in variousparallel and/or sequential combinations.

The flow of FIG. 3 involves exemplary device operations during powersaving mode 204. These operations are described with reference to a PSMP and one or more remote devices. These remote device(s) may be peerdevices. Alternatively, these remote device(s) may seek to establish apeer relationship with the power saving device. The operations of FIG. 3may occur in the context of FIG. 1. Moreover, the PS MP and/or theremote device(s) may include features, such as those described hereinwith reference to FIGS. 2 and 8.

At a block 302, the PS MP enters awake state 206. Upon entering awakestate 206, the PS MP sends a beacon transmission at a block 303. Thisbeacon provides an indication of an awake window time period. Forexample, this beacon may include the awake window information elementdescribed below with reference to FIG. 7. Embodiments, however, are notlimited to employing this information element.

At a block 304, the PS MP determines whether the awake window timeperiod has elapsed. If so, then operation proceeds to a block 350, wherethe PS MP enters doze state 208. Otherwise, performance of one or morepaths may occur. For example, FIG. 3 shows a path 360 that involves thePS MP sending transmissions to a peer device, a path 370 that involvesthe PS MP receiving transmissions from a peer device, and a path 380that involves the establishment of a new peer relationship. Such pathsmay be performed in various sequential and/or parallel orders.

FIG. 3 shows path 360 including blocks 305-308. At block 305, the PS MPindicates whether it has any buffered traffic (e.g., unicast traffic)for its peer devices. This indication may be included in a beacontransmission (such as the beacon sent at block 303). For instance, thePS MP may make this indication by setting one or more bits in its beaconframe. For example, in the context of 802.11s networks, the PS MP mayset a bit in the traffic indication map (TIM) element that matches thepeer device's peer link ID.

In turn, a peer device that receives this indication of buffered traffic(e.g., buffered unicast traffic) may send the PS MP a responsivetransmission (such as a trigger frame) to initiate a packet receptionperiod. Accordingly, as indicated by a block 307, the PS MP determineswhether it has received such a responsive transmission from the peerdevice. If so, then operation proceeds to a block 308. Otherwise,operation may return to block 304.

At block 308, the PS MP acknowledges the trigger frame and transmits itsbuffered traffic to the peer device. This may involve sending multiplebuffered packets to the peer device.

Once the buffered traffic has been sent, the PS MP may indicate itscompletion of data transmission to the peer device at a block 309. Inthe context of IEEE 802.11s networks, block 309 may include sending oneor more data frames having an End of Service Period (EOSP) bit set. FIG.3 shows that, following block 309, operation may return to block 304.

As described above, path 370 involves the PS MP receiving traffic from apeer device. FIG. 3 shows that path 370 may include blocks 310 and 312.

A peer device having buffered traffic to send to the PS MP stays awakeduring the awake interval following the power saving device's targetbeacon transmission time (TBTT). Thus, at a block 310, such a peerdevice may trigger a service period to deliver its buffered traffic tothe PS MP. This may involve the peer device sending one or moretriggering transmissions to the PS MP.

At a block 312, the PS MP receives the buffered traffic from the peerdevice. Following this, operation may return to block 304.

As indicated above, path 380 involves a peer connection beingestablished between the PS MP and a remote device. FIG. 3 shows thatpath 380 may include blocks 330-332.

At block 330, the PS MP enters into a peer link establishment process.Details regarding an exemplary peer link establishment process aredescribed below with reference to FIG. 4. Following completion (e.g.,successful completion or unsuccessful completion) of the peer linkestablishment process, operation may return to block 304.

As described herein, embodiments may employ a peer link establishmentprocess that may be performed after a device discovers another devicethat is in power saving mode 204 (e.g., a PS MP). As an example, such aprocess is performed at block 332 of FIG. 3.

Accordingly, FIG. 4 is a flow diagram showing exemplary operations of apeer link establishment process. Although FIG. 4 shows a particularsequence, other sequences may be employed. Also, the depicted operationsmay be performed in various parallel and/or sequential combinations.

The operations in FIG. 4 are described with reference to a device(referred to as the “new device”) that seeks to establish a peerrelationship with a PS MP. These operations may occur in the context ofFIG. 1. Moreover the new device and/or the power saving device mayinclude features, such as those described herein with reference to FIGS.2 and 8.

At a block 402 the new device may perform passive scanning to discoverexisting devices in a mesh network.

At a block 404, the new device receives a beacon from the PS MP. Thisbeacon indicates the power saving device's awake window. For example,this beacon may include an awake window information element, such as theone described below with reference to FIG. 7. However, other awakewindow indications may be employed.

Based on this beacon, at a block 406, the new device attempts to send apeer link open message to the PS MP before the end of its awake window.

As indicated by a block 408, the PS MP determines whether it hasreceived the peer link open message during its awake window. If so, thenoperations proceed to a block 410, and the PS MP remains in the awakestate until the peer link establishment process has been completed(either successfully or unsuccessfully). Otherwise, if the peer linkopen message is not received duing the PS MP's awake window, then thepeer link establishment process is unsuccessfully completed (asindicated by a block 409).

At block 410, the PS MP sends a peer link confirm message to the newdevice. Also, at a block 412, the PS MP sends a peer link open messageto the new device. In response to this peer link open message, the newdevice sends a peer link confirm message to the PS MP at a block 414.

Thus, this peer link establishment procedure involves a “doublehandshake” of peer link open and peer link confirm messages.Accordingly, a peer link is successfully established when both deviceshave sent and received peer link open and confirm messages.

Without an awake window, the PS MP may immediately go back to doze state208 after transmitting a beacon or after responding to the Peer LinkOpen message from the new MP.

However, to ensure that a pending double handshake can be completed,embodiments require a PS MP to stay awake (e.g., remain in awake state206) during its awake window, and to remain awake during a pending peerlink set up process. This may advantageously promote fast and successfulestablishment of peer links.

FIG. 5 is a diagram 500 showing exemplary device interactions. Inparticular, FIG. 5 shows interactions occurring between a first meshpoint 502 (which is in awake state 206) and a second mesh point 504.These interactions occur along a time axis 506. Through theseinteractions, a peer link is established.

As described above with reference to FIG. 4, establishment of such peerlinks may involve a double handshaking procedure. Accordingly, FIG. 5shows a first handshake 520 that begins with mesh point 504 sending apeer link open message 508. In response, mesh point 502 sends a peerlink confirm message 510 to mesh point 504. FIG. 5 further shows asecond handshake 522. This handshake involves mesh point 502 sending apeer link open message 512 to mesh point 504, and mesh point 504responding by sending a peer link confirm message to mesh point 502.

FIG. 6 is a diagram 600 showing a sequence of transmissions along a timeaxis 602. These transmissions are shown from the perspective of a localmesh point in awake state 206. In this diagram, upward pointing arrowsrepresent transmissions that are outgoing from the local mesh point,while downward pointing arrows represent transmissions that are incomingto the local mesh point.

As shown in FIG. 6, the local mesh point transmits beacons 604 and 606.Each of these beacons advertises an awake window. For example, beacon604 advertises an awake window 608. Within this window, a peer linkestablishment procedure begins. In particular, the local mesh pointreceives a peer link open (PLO) message 610 from a remote mesh point. Inresponse, the local mesh point sends a peer link confirm (PLC) message612 to the remote device. These two messages comprise a first handshake.As a second handshake, the local mesh point transmits a PLO message 614.In response, a PLC message 616 is received from the remote mesh point.

Through the exchange of these messages, a peer link is establishedbetween the local mesh point and the remote mesh point. FIG. 6 showsthat this peer link establishment procedure extends beyond awake window608. However, as described above with reference to FIG. 4, initiation ofthis procedure by the remote mesh point causes the local mesh point toremain awake until the procedure is completed.

FIG. 7 is a diagram of an awake window information element (IE) 700. Asdescribed herein, a beacon transmitted by a device in awake state 206may include this information element. As shown in FIG. 7, awake windowIE 700 includes an identifier (ID) field 702, a length field 704, and anawake window indicator field 706.

ID field 702 includes a predetermined value that identifies IE 700 as anawake window IE. Length field 704 indicates the size of IE 700. Inembodiments, the start of an awake window is measured from TBTT. Thus,awake window indicator field 706 indicates the length (or time duration)of the awake window from this starting point (the sending of a beacon).

FIG. 7 shows that identifier field 702 may have a size of one octet,length field 704 may have a size of one octet, and awake windowindicator field 706 may have a size of two octets. These sizes, as wellas the format of FIG. 7, are shown for purposes of illustration, and notlimitation. Accordingly, embodiments may employ other sizes and formats.

FIG. 8 is a diagram of an exemplary device implementation 800. Thisimplementation may be employed by devices, such as mesh points. Forexample, this implementation may be employed by devices 102 ₁-102 ₁₀ ofFIG. 1. However, this implementation may be also employed in othercontexts.

Implementation 800 may include various elements. For example, FIG. 8shows implementation 800 including an antenna 802, a transceiver module804, a host module 806, and a power control module 808. These elementsmay be implemented in hardware, software, firmware, or any combinationthereof.

Antenna 802 provides for the exchange of wireless signals with remotedevices. Although a single antenna is depicted, multiple antennas may beemployed. For example, embodiments may employ one or more transmitantennas and one or more receive antennas. Alternatively oradditionally, embodiments may employ multiple antennas for beamforming,and or phased-array antenna arrangements.

As shown in FIG. 8, transceiver module 804 includes a transmitterportion 810 and a receiver portion 812. During operation, transceivermodule 804 provides an interface between antenna 802 and host module806. For instance, transmitter portion 810 receives symbols 820 fromhost module 806 and generates corresponding signals 822 for wirelesstransmission by antenna module 802. This may involve operations, such asmodulation, amplification, and/or filtering. However, other operationsmay be employed.

Conversely, receiver portion 812 obtains signals 824 received by antenna802 and generates corresponding symbols 826. In turn, transceiver module804 provides symbols 826 to host module 806. This generation of symbols826 may involve operations, including (but not limited to) demodulation,amplification, and/or filtering.

To provide such features, transmitter portion 810 and receiver portion812 may each include various components, such as modulators,demodulators, amplifiers, filters, buffers, upconverters, and/ordownconveters. Such components may be implemented in hardware (e.g.,electronics), software, or any combination thereof.

The symbols exchanged between host module 806 and transceiver module 804may form messages or information associated with one or more protocols,and/or one or more user applications. Thus, host module 806 may performoperations corresponding to such protocol(s) and/or user application(s).Exemplary protocols include various media access control, network,transport and/or session layer protocols. Exemplary user applicationsinclude telephony, messaging, e-mail, web browsing, content (e.g., videoand audio) distribution/reception, and so forth.

Signals 822 and 824 may be in various formats. For instance, thesesignals may be formatted for transmission in IEEE 802.11s networks.However, embodiments are not limited to these exemplary networks.

In addition to operating as an interface between host module 806 andantenna 802, transceiver module 804 may perform various signaling, linkcontrol, and media access operations. For instance, transceiver module804 may generate and transmit beacons (via antenna 802), as well asexchange signaling messages (e.g., trigger messages, PLO messages, PLCmessages, and so forth). These operations may be coordinated by acontrol module 809 within transceiver module 804. As shown in FIG. 8,control module 809 is coupled to transmitter portion 810 and receiverportion 812.

Also, FIG. 8 shows that control module 809 is coupled to host module 806and power management module 808. Accordingly, control module 809 mayexchange information with these elements. Such information may includestatus information sent by control module 809 and operational directivesreceived by host module 806 and/or power management module 808.

Power control module 808 governs various operations of apparatus 800.For instance, power control module 808 establishes current operationalmodes and states of apparatus 800 (e.g., active mode 202, power savingmode 204, awake state 206, and doze state 208). As shown in FIG. 8, thismay be carried out through operational directives 832, which are sent tocontrol module 809 within transceiver module 804.

Power control module 808 may establish these modes and states based onvarious factors. Examples of such factors include (but are not limitedto) status information 830 that it receives from transceiver module 804,and/or configuration data 828 that it receives from host module 806.

Configuration data 828 may include power management policies andprocedures for power management module 808 to apply. Such policies andprocedures may include parameters such as beacon intervals, wakeupintervals, awake windows, and so forth. In embodiments, configurationdata 828 may be based (at least in part) on user settings andselections.

Status information 830 may indicate current operational status oftransceiver module 804. For instance, status information 830 mayindicate pending peer establishment processes. As described herein, suchprocesses may affect how long a device operates in awake state 206.However, in embodiments, status information 830 may additionally oralternatively include other forms of information.

FIG. 9 illustrates a logic flow 900, which may be representative of theoperations executed by one or more embodiments described herein.Although FIG. 9 shows a particular sequence, other sequences may beemployed. Also, the depicted operations may be performed in variousparallel and/or sequential combinations.

These operations are described with reference to a device. This devicemay be a mesh point, such as one of MPs 102 ₁-102 ₁₀ in FIG. 1.Accordingly, this device may include the implementation of FIG. 8.Embodiments, however, are not limited to these devices andimplementations.

At a block 902, the device determines a beacon interval and a wakeupinterval.

Following this determination, the device advertises the beacon intervaland wakeup interval to other devices at a block 904. In embodiments,this advertisement is performed while the device is awake (e.g., whilein active mode 202 or while in awake state 206).

At a block 906 the device enters a doze state. From this doze state, thedevice enters an awake state at block 908. While in this awake state,the device may perform various operation(s). Exemplary operations aredescribed below with reference to FIG. 3. For instance, the device maytransmit data, receive data, and/or engage in peer establishmentprocesses with remote devices. Embodiments, however, are not limited tothese operations.

As described herein, various embodiments may be implemented usinghardware elements, software elements, or any combination thereof.Examples of hardware elements may include processors, microprocessors,circuits, circuit elements (e.g., transistors, resistors, capacitors,inductors, and so forth), integrated circuits, application specificintegrated circuits (ASIC), programmable logic devices (PLD), digitalsignal processors (DSP), field programmable gate array (FPGA), logicgates, registers, semiconductor device, chips, microchips, chip sets,and so forth.

Examples of software may include software components, programs,applications, computer programs, application programs, system programs,machine programs, operating system software, middleware, firmware,software modules, routines, subroutines, functions, methods, procedures,software interfaces, application program interfaces (API), instructionsets, computing code, computer code, code segments, computer codesegments, words, values, symbols, or any combination thereof.

Some embodiments may be implemented, for example, using amachine-readable medium or article which may store an instruction or aset of instructions that, if executed by a machine, may cause themachine to perform a method and/or operations in accordance with theembodiments. Such a machine may include, for example, any suitableprocessing platform, computing platform, computing device, processingdevice, computing system, processing system, computer, processor, or thelike, and may be implemented using any suitable combination of hardwareand/or software.

The machine-readable medium or article may include, for example, anysuitable type of memory unit, memory device, memory article, memorymedium, storage device, storage article, storage medium and/or storageunit, for example, memory, removable or non-removable media, erasable ornon-erasable media, writeable or re-writeable media, digital or analogmedia, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM),Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW),optical disk, magnetic media, magneto-optical media, removable memorycards or disks, various types of Digital Versatile Disk (DVD), a tape, acassette, or the like. The instructions may include any suitable type ofcode, such as source code, compiled code, interpreted code, executablecode, static code, dynamic code, encrypted code, and the like,implemented using any suitable high-level, low-level, object-oriented,visual, compiled and/or interpreted programming language.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not in limitation. For example, the techniquesdescribed herein are not limited to IEEE 802.11s networks.

Accordingly, it will be apparent to persons skilled in the relevant artthat various changes in form and detail can be made therein withoutdeparting from the spirit and scope of the invention. Thus, the breadthand scope of the present invention should not be limited by any of theabove-described exemplary embodiments, but should be defined only inaccordance with the following claims and their equivalents.

1. An apparatus, comprising: a power management module to determine abeacon interval and a wakeup interval; and a transceiver module to senda transmission to one or more remote devices, the transmission includingthe beacon interval and the wakeup interval; wherein the beacon intervalindicates a time interval between consecutive beacon transmissions ofthe apparatus; and wherein the wakeup interval indicates a time intervalbetween when the apparatus receives two consecutive beacons from a peerdevice.
 2. The apparatus of claim 1, wherein the transceiver module isto send the transmission when the apparatus is in an awake state.
 3. Theapparatus of claim 2, wherein the transmission is a beacon transmission.4. The apparatus of claim 1, wherein the power management module directsthe apparatus to transition between two or more operational states, thetwo or more operational states comprising an awake state and a dozestate.
 5. The apparatus of claim 1, wherein, upon the apparatus enteringan awake state from a doze state, the transceiver module is to transmita beacon comprising an awake window time period.
 6. The apparatus ofclaim 5, wherein the transceiver module is to commence in aremotely-initiated peer establishment procedure during the awake windowtime period.
 7. The apparatus of claim 6, wherein the power managementmodule is to direct the apparatus to enter a doze state from the awakestate when the awake window time period has elapsed and the peerestablishment procedure is completed.
 8. The apparatus of claim 6,wherein the remotely-initiated peer establishment procedure comprisesthe transceiver: receiving a first peer link open (PLO) message from aremote device; sending, in response to the first PLO message, a firstpeer link confirm (PLC) message to the remote device; sending a secondPLO message to the remote device; and receiving, in response to thesecond PLO message, a second PLC message from the remote device.
 9. Theapparatus of claim 5, wherein the transceiver module is to transmitbuffered traffic during the awake window time period.
 10. A method,comprising: entering an awake state from a doze state; advertising anawake window time period; commencing a remotely initiated peerestablishment procedure during the awake window time period; andreturning to the doze state when the awake window time period haselapsed and the remotely-initiated peer establishment procedure iscompleted.
 11. The method of claim 10, wherein engaging in theremotely-initiated peer establishment procedure comprises performing adouble handshaking procedure with the remote device.
 12. The method ofclaim 11, wherein the double handshaking procedure comprises: receivinga first peer link open (PLO) message from a remote device; sending, inresponse to the first PLO message, a first peer link confirm (PLC)message to the remote device; sending a second PLO message to the remotedevice; and receiving, in response to the second PLO message, a secondPLC message from the remote device.
 13. The method of claim 10, whereinadvertising the awake window time period comprises transmitting a beaconcomprising an awake window information element.
 14. The method of claim13, wherein the awake window information element comprises a field toindicate a duration of the awake window time period from a target beacontransmission time (TBTT).
 15. The method of claim 10, further comprisingsending buffered traffic during the awake window time period.
 16. Anarticle comprising a machine-accessible medium having stored thereoninstructions that, when executed by a machine, cause the machine to:enter an awake state from a doze state; advertise an awake window timeperiod; commence a remotely initiated peer establishment procedureduring the awake window time period; and return to the doze state whenthe awake window time period has elapsed and the remotely-initiated peerestablishment procedure is completed.
 17. The article of claim 16,wherein the instructions, when executed by a machine, cause the machineto advertise the awake window time period in a beacon comprising anawake window information element.
 18. The article of claim 17, whereinthe awake window information element comprises a field to indicate aduration of the awake window time period from a target beacontransmission time (TBTT).
 19. The article of claim 16, wherein theremotely-initiated peer establishment procedure involves a doublehandshaking procedure with the remote device.
 20. The article of claim16, wherein the instructions, when executed by a machine, further causethe machine to send buffered traffic during the awake window timeperiod.